1 /* $NetBSD: pwcache.c,v 1.31 2010/03/23 20:28:59 drochner Exp $ */ 2 3 /*- 4 * Copyright (c) 1992 Keith Muller. 5 * Copyright (c) 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Keith Muller of the University of California, San Diego. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 /*- 37 * Copyright (c) 2002 The NetBSD Foundation, Inc. 38 * All rights reserved. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 50 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 52 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 59 * POSSIBILITY OF SUCH DAMAGE. 60 */ 61 62 #if HAVE_NBTOOL_CONFIG_H 63 #include "nbtool_config.h" 64 /* 65 * XXX Undefine the renames of these functions so that we don't 66 * XXX rename the versions found in the host's <pwd.h> by mistake! 67 */ 68 #undef group_from_gid 69 #undef user_from_uid 70 #endif 71 72 #include <sys/cdefs.h> 73 #if defined(LIBC_SCCS) && !defined(lint) 74 #if 0 75 static char sccsid[] = "@(#)cache.c 8.1 (Berkeley) 5/31/93"; 76 #else 77 __RCSID("$NetBSD: pwcache.c,v 1.31 2010/03/23 20:28:59 drochner Exp $"); 78 #endif 79 #endif /* LIBC_SCCS and not lint */ 80 81 #include "namespace.h" 82 83 #include <sys/types.h> 84 #include <sys/param.h> 85 86 #include <assert.h> 87 #include <grp.h> 88 #include <pwd.h> 89 #include <stdio.h> 90 #include <stdlib.h> 91 #include <string.h> 92 #include <unistd.h> 93 94 #define _DIAGASSERT(x) assert((x)) 95 96 #if HAVE_NBTOOL_CONFIG_H 97 /* XXX Now, re-apply the renaming that we undid above. */ 98 #define group_from_gid __nbcompat_group_from_gid 99 #define user_from_uid __nbcompat_user_from_uid 100 #endif 101 102 #ifdef __weak_alias 103 __weak_alias(user_from_uid,_user_from_uid) 104 __weak_alias(group_from_gid,_group_from_gid) 105 __weak_alias(pwcache_groupdb,_pwcache_groupdb) 106 #endif 107 108 #if !HAVE_PWCACHE_USERDB || HAVE_NBTOOL_CONFIG_H 109 #include "pwcache.h" 110 111 /* 112 * routines that control user, group, uid and gid caches (for the archive 113 * member print routine). 114 * IMPORTANT: 115 * these routines cache BOTH hits and misses, a major performance improvement 116 */ 117 118 /* 119 * function pointers to various name lookup routines. 120 * these may be changed as necessary. 121 */ 122 static int (*_pwcache_setgroupent)(int) = setgroupent; 123 static void (*_pwcache_endgrent)(void) = endgrent; 124 static struct group * (*_pwcache_getgrnam)(const char *) = getgrnam; 125 static struct group * (*_pwcache_getgrgid)(gid_t) = getgrgid; 126 static int (*_pwcache_setpassent)(int) = setpassent; 127 static void (*_pwcache_endpwent)(void) = endpwent; 128 static struct passwd * (*_pwcache_getpwnam)(const char *) = getpwnam; 129 static struct passwd * (*_pwcache_getpwuid)(uid_t) = getpwuid; 130 131 /* 132 * internal state 133 */ 134 static int pwopn; /* is password file open */ 135 static int gropn; /* is group file open */ 136 static UIDC **uidtb; /* uid to name cache */ 137 static GIDC **gidtb; /* gid to name cache */ 138 static UIDC **usrtb; /* user name to uid cache */ 139 static GIDC **grptb; /* group name to gid cache */ 140 141 static int uidtb_fail; /* uidtb_start() failed ? */ 142 static int gidtb_fail; /* gidtb_start() failed ? */ 143 static int usrtb_fail; /* usrtb_start() failed ? */ 144 static int grptb_fail; /* grptb_start() failed ? */ 145 146 147 static u_int st_hash(const char *, size_t, int); 148 static int uidtb_start(void); 149 static int gidtb_start(void); 150 static int usrtb_start(void); 151 static int grptb_start(void); 152 153 154 static u_int 155 st_hash(const char *name, size_t len, int tabsz) 156 { 157 u_int key = 0; 158 159 _DIAGASSERT(name != NULL); 160 161 while (len--) { 162 key += *name++; 163 key = (key << 8) | (key >> 24); 164 } 165 166 return (key % tabsz); 167 } 168 169 /* 170 * uidtb_start 171 * creates an an empty uidtb 172 * Return: 173 * 0 if ok, -1 otherwise 174 */ 175 static int 176 uidtb_start(void) 177 { 178 179 if (uidtb != NULL) 180 return (0); 181 if (uidtb_fail) 182 return (-1); 183 if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) { 184 ++uidtb_fail; 185 return (-1); 186 } 187 return (0); 188 } 189 190 /* 191 * gidtb_start 192 * creates an an empty gidtb 193 * Return: 194 * 0 if ok, -1 otherwise 195 */ 196 static int 197 gidtb_start(void) 198 { 199 200 if (gidtb != NULL) 201 return (0); 202 if (gidtb_fail) 203 return (-1); 204 if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) { 205 ++gidtb_fail; 206 return (-1); 207 } 208 return (0); 209 } 210 211 /* 212 * usrtb_start 213 * creates an an empty usrtb 214 * Return: 215 * 0 if ok, -1 otherwise 216 */ 217 static int 218 usrtb_start(void) 219 { 220 221 if (usrtb != NULL) 222 return (0); 223 if (usrtb_fail) 224 return (-1); 225 if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) { 226 ++usrtb_fail; 227 return (-1); 228 } 229 return (0); 230 } 231 232 /* 233 * grptb_start 234 * creates an an empty grptb 235 * Return: 236 * 0 if ok, -1 otherwise 237 */ 238 static int 239 grptb_start(void) 240 { 241 242 if (grptb != NULL) 243 return (0); 244 if (grptb_fail) 245 return (-1); 246 if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) { 247 ++grptb_fail; 248 return (-1); 249 } 250 return (0); 251 } 252 253 /* 254 * user_from_uid() 255 * caches the name (if any) for the uid. If noname clear, we always 256 * return the stored name (if valid or invalid match). 257 * We use a simple hash table. 258 * Return 259 * Pointer to stored name (or a empty string) 260 */ 261 const char * 262 user_from_uid(uid_t uid, int noname) 263 { 264 struct passwd *pw; 265 UIDC *ptr, **pptr; 266 267 if ((uidtb == NULL) && (uidtb_start() < 0)) 268 return (NULL); 269 270 /* 271 * see if we have this uid cached 272 */ 273 pptr = uidtb + (uid % UID_SZ); 274 ptr = *pptr; 275 276 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) { 277 /* 278 * have an entry for this uid 279 */ 280 if (!noname || (ptr->valid == VALID)) 281 return (ptr->name); 282 return (NULL); 283 } 284 285 /* 286 * No entry for this uid, we will add it 287 */ 288 if (!pwopn) { 289 if (_pwcache_setpassent != NULL) 290 (*_pwcache_setpassent)(1); 291 ++pwopn; 292 } 293 294 if (ptr == NULL) 295 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 296 297 if ((pw = (*_pwcache_getpwuid)(uid)) == NULL) { 298 /* 299 * no match for this uid in the local password file 300 * a string that is the uid in numeric format 301 */ 302 if (ptr == NULL) 303 return (NULL); 304 ptr->uid = uid; 305 (void)snprintf(ptr->name, UNMLEN, "%lu", (long) uid); 306 ptr->valid = INVALID; 307 if (noname) 308 return (NULL); 309 } else { 310 /* 311 * there is an entry for this uid in the password file 312 */ 313 if (ptr == NULL) 314 return (pw->pw_name); 315 ptr->uid = uid; 316 (void)strlcpy(ptr->name, pw->pw_name, UNMLEN); 317 ptr->valid = VALID; 318 } 319 return (ptr->name); 320 } 321 322 /* 323 * group_from_gid() 324 * caches the name (if any) for the gid. If noname clear, we always 325 * return the stored name (if valid or invalid match). 326 * We use a simple hash table. 327 * Return 328 * Pointer to stored name (or a empty string) 329 */ 330 const char * 331 group_from_gid(gid_t gid, int noname) 332 { 333 struct group *gr; 334 GIDC *ptr, **pptr; 335 336 if ((gidtb == NULL) && (gidtb_start() < 0)) 337 return (NULL); 338 339 /* 340 * see if we have this gid cached 341 */ 342 pptr = gidtb + (gid % GID_SZ); 343 ptr = *pptr; 344 345 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) { 346 /* 347 * have an entry for this gid 348 */ 349 if (!noname || (ptr->valid == VALID)) 350 return (ptr->name); 351 return (NULL); 352 } 353 354 /* 355 * No entry for this gid, we will add it 356 */ 357 if (!gropn) { 358 if (_pwcache_setgroupent != NULL) 359 (*_pwcache_setgroupent)(1); 360 ++gropn; 361 } 362 363 if (ptr == NULL) 364 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 365 366 if ((gr = (*_pwcache_getgrgid)(gid)) == NULL) { 367 /* 368 * no match for this gid in the local group file, put in 369 * a string that is the gid in numberic format 370 */ 371 if (ptr == NULL) 372 return (NULL); 373 ptr->gid = gid; 374 (void)snprintf(ptr->name, GNMLEN, "%lu", (long) gid); 375 ptr->valid = INVALID; 376 if (noname) 377 return (NULL); 378 } else { 379 /* 380 * there is an entry for this group in the group file 381 */ 382 if (ptr == NULL) 383 return (gr->gr_name); 384 ptr->gid = gid; 385 (void)strlcpy(ptr->name, gr->gr_name, GNMLEN); 386 ptr->valid = VALID; 387 } 388 return (ptr->name); 389 } 390 391 /* 392 * uid_from_user() 393 * caches the uid for a given user name. We use a simple hash table. 394 * Return 395 * the uid (if any) for a user name, or a -1 if no match can be found 396 */ 397 int 398 uid_from_user(const char *name, uid_t *uid) 399 { 400 struct passwd *pw; 401 UIDC *ptr, **pptr; 402 size_t namelen; 403 404 /* 405 * return -1 for mangled names 406 */ 407 if (name == NULL || ((namelen = strlen(name)) == 0)) 408 return (-1); 409 if ((usrtb == NULL) && (usrtb_start() < 0)) 410 return (-1); 411 412 /* 413 * look up in hash table, if found and valid return the uid, 414 * if found and invalid, return a -1 415 */ 416 pptr = usrtb + st_hash(name, namelen, UNM_SZ); 417 ptr = *pptr; 418 419 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 420 if (ptr->valid == INVALID) 421 return (-1); 422 *uid = ptr->uid; 423 return (0); 424 } 425 426 if (!pwopn) { 427 if (_pwcache_setpassent != NULL) 428 (*_pwcache_setpassent)(1); 429 ++pwopn; 430 } 431 432 if (ptr == NULL) 433 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 434 435 /* 436 * no match, look it up, if no match store it as an invalid entry, 437 * or store the matching uid 438 */ 439 if (ptr == NULL) { 440 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) 441 return (-1); 442 *uid = pw->pw_uid; 443 return (0); 444 } 445 (void)strlcpy(ptr->name, name, UNMLEN); 446 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) { 447 ptr->valid = INVALID; 448 return (-1); 449 } 450 ptr->valid = VALID; 451 *uid = ptr->uid = pw->pw_uid; 452 return (0); 453 } 454 455 /* 456 * gid_from_group() 457 * caches the gid for a given group name. We use a simple hash table. 458 * Return 459 * the gid (if any) for a group name, or a -1 if no match can be found 460 */ 461 int 462 gid_from_group(const char *name, gid_t *gid) 463 { 464 struct group *gr; 465 GIDC *ptr, **pptr; 466 size_t namelen; 467 468 /* 469 * return -1 for mangled names 470 */ 471 if (name == NULL || ((namelen = strlen(name)) == 0)) 472 return (-1); 473 if ((grptb == NULL) && (grptb_start() < 0)) 474 return (-1); 475 476 /* 477 * look up in hash table, if found and valid return the uid, 478 * if found and invalid, return a -1 479 */ 480 pptr = grptb + st_hash(name, namelen, GID_SZ); 481 ptr = *pptr; 482 483 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 484 if (ptr->valid == INVALID) 485 return (-1); 486 *gid = ptr->gid; 487 return (0); 488 } 489 490 if (!gropn) { 491 if (_pwcache_setgroupent != NULL) 492 (*_pwcache_setgroupent)(1); 493 ++gropn; 494 } 495 496 if (ptr == NULL) 497 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 498 499 /* 500 * no match, look it up, if no match store it as an invalid entry, 501 * or store the matching gid 502 */ 503 if (ptr == NULL) { 504 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) 505 return (-1); 506 *gid = gr->gr_gid; 507 return (0); 508 } 509 510 (void)strlcpy(ptr->name, name, GNMLEN); 511 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) { 512 ptr->valid = INVALID; 513 return (-1); 514 } 515 ptr->valid = VALID; 516 *gid = ptr->gid = gr->gr_gid; 517 return (0); 518 } 519 520 #define FLUSHTB(arr, len, fail) \ 521 do { \ 522 if (arr != NULL) { \ 523 for (i = 0; i < len; i++) \ 524 if (arr[i] != NULL) \ 525 free(arr[i]); \ 526 arr = NULL; \ 527 } \ 528 fail = 0; \ 529 } while (/* CONSTCOND */0); 530 531 int 532 pwcache_userdb( 533 int (*a_setpassent)(int), 534 void (*a_endpwent)(void), 535 struct passwd * (*a_getpwnam)(const char *), 536 struct passwd * (*a_getpwuid)(uid_t)) 537 { 538 int i; 539 540 /* a_setpassent and a_endpwent may be NULL */ 541 if (a_getpwnam == NULL || a_getpwuid == NULL) 542 return (-1); 543 544 if (_pwcache_endpwent != NULL) 545 (*_pwcache_endpwent)(); 546 FLUSHTB(uidtb, UID_SZ, uidtb_fail); 547 FLUSHTB(usrtb, UNM_SZ, usrtb_fail); 548 pwopn = 0; 549 _pwcache_setpassent = a_setpassent; 550 _pwcache_endpwent = a_endpwent; 551 _pwcache_getpwnam = a_getpwnam; 552 _pwcache_getpwuid = a_getpwuid; 553 554 return (0); 555 } 556 557 int 558 pwcache_groupdb( 559 int (*a_setgroupent)(int), 560 void (*a_endgrent)(void), 561 struct group * (*a_getgrnam)(const char *), 562 struct group * (*a_getgrgid)(gid_t)) 563 { 564 int i; 565 566 /* a_setgroupent and a_endgrent may be NULL */ 567 if (a_getgrnam == NULL || a_getgrgid == NULL) 568 return (-1); 569 570 if (_pwcache_endgrent != NULL) 571 (*_pwcache_endgrent)(); 572 FLUSHTB(gidtb, GID_SZ, gidtb_fail); 573 FLUSHTB(grptb, GNM_SZ, grptb_fail); 574 gropn = 0; 575 _pwcache_setgroupent = a_setgroupent; 576 _pwcache_endgrent = a_endgrent; 577 _pwcache_getgrnam = a_getgrnam; 578 _pwcache_getgrgid = a_getgrgid; 579 580 return (0); 581 } 582 583 584 #ifdef TEST_PWCACHE 585 586 struct passwd * 587 test_getpwnam(const char *name) 588 { 589 static struct passwd foo; 590 591 memset(&foo, 0, sizeof(foo)); 592 if (strcmp(name, "toor") == 0) { 593 foo.pw_uid = 666; 594 return &foo; 595 } 596 return (getpwnam(name)); 597 } 598 599 int 600 main(int argc, char *argv[]) 601 { 602 uid_t u; 603 int r, i; 604 605 printf("pass 1 (default userdb)\n"); 606 for (i = 1; i < argc; i++) { 607 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 608 i, pwopn, usrtb_fail, usrtb); 609 r = uid_from_user(argv[i], &u); 610 if (r == -1) 611 printf(" uid_from_user %s: failed\n", argv[i]); 612 else 613 printf(" uid_from_user %s: %d\n", argv[i], u); 614 } 615 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n", 616 pwopn, usrtb_fail, usrtb); 617 618 puts(""); 619 printf("pass 2 (replacement userdb)\n"); 620 printf("pwcache_userdb returned %d\n", 621 pwcache_userdb(setpassent, test_getpwnam, getpwuid)); 622 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb); 623 624 for (i = 1; i < argc; i++) { 625 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 626 i, pwopn, usrtb_fail, usrtb); 627 u = -1; 628 r = uid_from_user(argv[i], &u); 629 if (r == -1) 630 printf(" uid_from_user %s: failed\n", argv[i]); 631 else 632 printf(" uid_from_user %s: %d\n", argv[i], u); 633 } 634 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n", 635 pwopn, usrtb_fail, usrtb); 636 637 puts(""); 638 printf("pass 3 (null pointers)\n"); 639 printf("pwcache_userdb returned %d\n", 640 pwcache_userdb(NULL, NULL, NULL)); 641 642 return (0); 643 } 644 #endif /* TEST_PWCACHE */ 645 #endif /* !HAVE_PWCACHE_USERDB */ 646